Full Definition of COMPACT

a: having a dense structure or parts or units closely packed or joined <a compact woolen><compact bone>

b: not diffuse or verbose <a compact statement>

c: occupying a small volume by reason of efficient use of space <a compact camera><a compact formation of troops>

d: short-bodied, solid, and without excess flesh

3

: being a topological space and especially a metric space with the property that for any collection of open sets which contains it there is a subset of the collection with a finite number of elements which also contains it